Makita DBM230 Notice Originale page 26

The vacuum pump has to run during the complete operation, it is to be
placed in such a way that you can always observe the pressure gauge. It
is mandatory to check that the foot plate is firmly affixed before you start
drilling.
Fixing the mount by means of clamping device
In order to brace the drill mount by means of a clamping device, the
distance between the opposite wall must be between 1,7 m and 3 m.
Caution! The drill stand must be firmly connected to the surface.
Otherwise the operator might suffer injuries or the drill could be
damaged.
Uncontrolled movements during drilling will cause the drill bit to hit the
surface to be drilled, this may cause chipping of the segments. The drill
bit might also tilt in the borehole which will also damage it.
Execution of drilling
Switch the GFCI to ON.
Open the water supply.
Switch the motor ON, the drill bit must not yet touch the surface.
Lower the drill bit until it touches the surface.
In order to achieve an exact centering of the drill bit, minimize the
forward travel of the drill bit during he first centimeter of cutting depth.
Now you can increase the drilling speed to the correct speed for the
core bit in use. If the drilling speed is too high, the diamond segments
will become blunt in short time.
Inclined drilling
Remove the bolt in the foot plate, which holds the column at a 90º
angle.
Loosen the thumb screw between support and column and swivel the
column to the desired angle.
Tighten the two bolts again.
At the start of drilling, use low drill speed as only a portion of the drill
bit touches the surface. If the drill speed or pressure is too high the drill
bit may become erratic.
Position the drill mount. Position the clamping device as close
as possible behind the column on the base of the mount. Fix
the mount by turning the crank (G) clockwise.
Secure the installation with the appropriate bolt (H).